The iteration of the EP receiver is performed until the values of \(\hat{{\bf x}}^{(t)}\)  and \({\bf v}^{(t)} \)  in () are close to those of \({\mu }^{(t)}_{\rm obs}\)  and \({\Sigma }^{(t)}_{\rm obs}\)  in (), respectively. This is referred to as the moment matching condition [1]}. When the moment matching condition has not been satisfied, the EP receiver recomputes the parameters \(\left({\gamma }^{(t+1)},{\lambda }^{(t+1)} \right)\)  in () by using () and a predefined learning parameter, \(\beta \) . Note that \(\beta \)  is used to weight the parameters, \(\left({\gamma }^{(t+1)},{\lambda }^{(t+1)}\right)\)  in two consecutive iterations.
